PicoContainer example source code file (VerifyingVisitor.java)

This example PicoContainer source code file (VerifyingVisitor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - PicoContainer tags/keywords

arraylist, componentadaptercollector, list, object, object, picocontainer, picoverificationexception, picoverificationexception, picovisitor, picovisitor, set, traversalcheckingvisitor, util, verifyingvisitor, verifyingvisitor

The PicoContainer VerifyingVisitor.java source code

/*****************************************************************************
 * Copyright (C) PicoContainer Organization. All rights reserved.            *
 * ------------------------------------------------------------------------- *
 * The software in this package is published under the terms of the BSD      *
 * style license a copy of which has been included with this distribution in *
 * the LICENSE.txt file.                                                     *
 *****************************************************************************/
package org.picocontainer.visitors;

import org.picocontainer.ComponentAdapter;
import org.picocontainer.Parameter;
import org.picocontainer.PicoContainer;
import org.picocontainer.PicoVerificationException;
import org.picocontainer.PicoVisitor;
import org.picocontainer.visitors.TraversalCheckingVisitor;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;


/**
 * Visitor to verify {@link PicoContainer} instances. The visitor walks down the logical container hierarchy.
 * 
 * @author Jörg Schaible
 */
public class VerifyingVisitor extends TraversalCheckingVisitor {

    private final List nestedVerificationExceptions;
    private final Set verifiedComponentAdapters;
    private final PicoVisitor componentAdapterCollector;
    private PicoContainer currentPico;

    /**
     * Construct a VerifyingVisitor.
     */
    public VerifyingVisitor() {
        nestedVerificationExceptions = new ArrayList();
        verifiedComponentAdapters = new HashSet();
        componentAdapterCollector = new ComponentAdapterCollector();
    }

    /**
     * Traverse through all components of the {@link PicoContainer} hierarchy and verify the components.
     * 
     * @throws PicoVerificationException if some components could not be verified.
     * @see org.picocontainer.PicoVisitor#traverse(java.lang.Object)
     */
    public Object traverse(Object node) throws PicoVerificationException {
        nestedVerificationExceptions.clear();
        verifiedComponentAdapters.clear();
        try {
            super.traverse(node);
            if (!nestedVerificationExceptions.isEmpty()) {
                throw new PicoVerificationException(new ArrayList(nestedVerificationExceptions));
            }
        } finally {
            nestedVerificationExceptions.clear();
            verifiedComponentAdapters.clear();
        }
        return Void.TYPE;
    }

    public void visitContainer(PicoContainer pico) {
        super.visitContainer(pico);
        currentPico = pico;
    }

    public void visitComponentAdapter(ComponentAdapter componentAdapter) {
        super.visitComponentAdapter(componentAdapter);
        if (!verifiedComponentAdapters.contains(componentAdapter)) {
            try {
                componentAdapter.verify(currentPico);
            } catch (RuntimeException e) {
                nestedVerificationExceptions.add(e);
            }
            componentAdapter.accept(componentAdapterCollector);
        }
    }

    private class ComponentAdapterCollector implements PicoVisitor {
        // /CLOVER:OFF
        public Object traverse(Object node) {
            return null;
        }

        public void visitContainer(PicoContainer pico) {
        }

        // /CLOVER:ON

        public void visitComponentAdapter(ComponentAdapter componentAdapter) {
            verifiedComponentAdapters.add(componentAdapter);
        }

        public void visitParameter(Parameter parameter) {
        }
    }
}